U.S. patent application number 10/216672 was filed with the patent office on 2003-03-13 for surgical device for retrieval of foreign objects from a body.
Invention is credited to Khachin, Stepan, Khachin, Vladimir.
Application Number | 20030050663 10/216672 |
Document ID | / |
Family ID | 11043063 |
Filed Date | 2003-03-13 |
United States Patent
Application |
20030050663 |
Kind Code |
A1 |
Khachin, Stepan ; et
al. |
March 13, 2003 |
Surgical device for retrieval of foreign objects from a body
Abstract
A surgical device for removing a foreign object from a body is
described. The device includes a retrieval basket for entrapping
and retaining the object located in the body, a basket control
assembly comprising a tubular sheath adapted to penetrate into the
body for reaching the object, and a manipulator for manipulating
the basket for extraction the object from the body. The basket
comprises a structure having a proximal end and a distal end. The
structure is formed by a plurality of filaments fabricated from a
single or several wires. The filaments extend from the proximal end
towards the distal end. At least a part of the filaments are
configured in the form of loops. At least a part of the loops are
interlaced so as to define a net at the distal end, and thereby
impart structural rigidity and dilatation ability to the basket
when opened.
Inventors: |
Khachin, Stepan; (Tomsk,
RU) ; Khachin, Vladimir; (Tomsk, RU) |
Correspondence
Address: |
BROWDY AND NEIMARK, P.L.L.C.
624 Ninth Street, N.W.
Washington
DC
20001
US
|
Family ID: |
11043063 |
Appl. No.: |
10/216672 |
Filed: |
August 12, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10216672 |
Aug 12, 2002 |
|
|
|
PCT/IL01/00591 |
Jun 29, 2001 |
|
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Current U.S.
Class: |
606/200 |
Current CPC
Class: |
A61B 2017/00526
20130101; A61B 2017/2212 20130101; A61B 17/221 20130101 |
Class at
Publication: |
606/200 |
International
Class: |
A61M 029/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jun 29, 2001 |
WO |
PCT/IL01/00591 |
Claims
1. A retrieval basket for entrapping and retaining an object
located in a body for its extraction therefrom, the basket
comprising a structure having a proximal end and a distal end and
constituted by a plurality of filaments extending from the proximal
end towards the distal end and being in the form of loops,
characterized in that at least a part of the loops are interlaced
so as to define a net at least in the vicinity of the distal end,
thereby imparting structural rigidity and dilatation abilities to
the basket when opened.
2. The basket of claim 1 wherein the net is formed of cells having
a size decreasing from the proximal end towards the distal end.
3. The basket of claim 1 wherein the structure is fabricated from a
single length of wire.
4. The basket of claim 11 wherein the structure is fabricated from
several wires.
5. The basket of claim 1 wherein the filaments in a region of the
structure at the proximal end form at least two strands each
including a plurality of the filaments.
6. The basket of claim 1 wherein the filaments in a region of the
structure at the proximal end form a plurality of stands, one of
the strands is common for all the filaments.
7. The basket of claim 1 wherein at least a part of the filaments,
which originate from the proximal end, also arrive at the proximal
end after winding.
8. The basket of claim 5 wherein said structure has a
parachute-like shape.
9. The basket of claim 6 wherein said structure has a spoon-like
shape.
10. The basket of claim 1 wherein at least some of the loops are
twisted and configured in a 8-like fashion.
11. The basket of claim 1 wherein distal ends of the loops are
bound together to form a basket tip.
12. The basket of claim 1 wherein the filaments are made of
metallic material.
13. The basket of claim 12 Wherein said metallic material has
thermo-mechanical shape memory characteristic.
14. The basket of claim 12 Wherein said metallic material is
selected from NiTi based alloy and stainless steel.
15. The basket of claim 1 wherein the filaments are made of
non-metallic material.
16. The basket of claim 15 wherein said non-metallic material is
Capron.
17. The basket of claim 1 wherein the filaments are covered by a
coating layer.
18. The basket of claim 17 wherein said coating layer is made of
Teflon.
19. A surgical device for removing a foreign object from a body,
comprising: a retrieval basket for entrapping and retaining the
object the basket comprising a structure having a proximal end and
a distal end and constituted by a plurality of filaments extending
from the proximal end towards the distal end and being in the form
of loops; at least a part of the loops are interlaced so as to
define a net at least in the vicinity of the distal end, and
thereby imparting structural rigidity and dilatation abilities to
the basket when opened; and a basket control assembly coupled to
the basket, comprising a tubular sheath adapted to penetrate into
tae body for reaching the object, and a manipulator for
manipulating the basket for extraction the object from the body,
the assembly is configured for retracting the basket within the
sheath and protracting the basket therefrom for its opening.
20. The device of claim 19 further comprising a pushing element
arranged within the sheath for connecting the basket to the
manipulator.
21. The device of claim 20 wherein said pushing element is
constituted by said plurality of filaments extending from said
proximal end towards the manipulator.
22. The device of claim 20 wherein said pushing element is
configured as a separate unit selected from a rod, cable and
wire.
23. The device of claim 19 wherein the net is formed of cells
having a size decreasing from the proximal end towards the distal
end.
24. The device of claim 19 wherein the structure is fabricated from
a single length of wire.
25. The device of claim 19 wherein the structure is fabricated from
several wires.
26. The device of claim 19 wherein the filaments in a region of the
structure at the proximal end form at least two strands each
including a plurality of the filaments.
27. The device of claim 19 wherein the filaments in a region of the
structure at the proximal end form a plurality of strands, one of
the strands is common for all the filaments.
28. The device of claim 19 wherein at least some of the loops are
twisted and configured in a 8-like fashion;
29. The device of claim 19 wherein distal ends of the loops are
bound together to form a basket tip.
30. The device of claim 19 wherein the filaments are made of
metallic material.
31. The device of claim 30 wherein said metallic material has
thermo-mechanical shape memory characteristic.
32. The device of claim 30 wherein said metallic material is
selected from NiTi based alloy and stainless steel.
33. The device of claim 31 further comprising a controllable power
supply source coupled to the filaments for passing electric current
therethrough.
34. The device of claim 19 wherein the filaments are made of
non-metallic material.
35. The device of claim 34 wherein said non-metallic material is
Capron.
36. The device of claim 19 wherein the filaments are covered by a
coating layer.
37. The device of claim 36 wherein said coating layer is made of
Teflon.
Description
FIELD OF THE INVENTION
[0001] This invention relates to a medical instrument for removing
an object from a body, and in particular, to a surgical device for
extracting calculi appearing in the biliary or urinary system.
BACKGROUND OF THE INVENTION
[0002] Despite the fact that by virtue of available modern
video-assisted endoscopic instrumentation significant progress has
been achieved in urological invasive treatment in general and in
the extracting of foreign objects in particular, the evacuation of
such objects like calculi from a surgical patient's body still
remains a challenge for a surgeon.
[0003] In the course of complicated and time-consuming surgical
treatment the removal of calculi of different sizes and
characteristics from various sites along the urinary tract and from
various locations within the body, (e.g. removal of gallstones and
kidney stones) becomes essential. This challenge has resulted in
the is development of a variety of surgical tools for stone
retrieval without the need for major surgery. The calculi retrieval
tools, or so-called surgical extractors usually comprise a flexible
tubular catheter formed as a tubular sheath adapted to penetrate
along the body passages to reach the location of the object to be
evacuated. A wire or cable is inserted within the catheter, which
can be manipulated from the outside at the catheter's proximal end.
The cable is connected to a basket deployed within the sheath at
the catheter's distal end. The basket consists of flexible
filaments made of either a memory shape material (e.g., stainless
steel) or any other material capable of providing the basket with
elasticity.
[0004] Depending on the manipulation, the basket may either retract
inside the sheath to allow penetration of the catheter via passage
or protract from the catheter. In the protracted position, the
wires open due to the elasticity of their material and form a cage
thus allowing the object to enter inside the basket through the
open spaces left between its adjacent wires. Further retraction of
the basket inside the sheath results in collapsing the cage and
entrapping the object in the basket. Removal of the catheter will
enable the whole device to be removed from the body organ together
with the object immobilized within the basket.
[0005] It can be easily appreciated that the particular design of
the basket-like element is crucial for entrapping and reliable
retaining the object during evacuation.
[0006] Various attempts to devise the basket are known in the art.
Examples of conventional baskets can be found in the web site
www.bsci.com. According to the recent classification suggested by
Boston Scientific Corporation, the currently employed baskets for
stone retrieval can be broadly categorized into the following
groups: (11) Flatwire baskets, (12) Helical baskets and (13)
Multi-wire baskets.
[0007] An example of a flatwire basket is disclosed in U.S. Pat.
No. 6,183,482. This basket comprises one or more legs to retrieve
the calculi. At least one of the legs has an inner surface and an
outer surface. The outer surface is curved to render the basket
atraumatic. he inner surface can be flat such that the leg has a
D-shaped cross-sectional configuration. It is reported in the
literature that flatwire baskets minimize lateral basket wire
movement and his facilitates and improves stone capture.
Furthermore, flatwire baskets open reliably even in an undilated
ureter. Flatwire baskets are available in a wide range of sizes and
wire configurations. A method of manufacturing of such baskets is
described, for example, in U.S. Pat. No. 5,658,296.
[0008] The intrinsic disadvantage of flatwire baskets is their
unsuitability for capturing and immobilizing relatively small
calculi, since the amount of wires in such baskets is limited to
very few and the size of open space between the adjacent wires
remains too large.
[0009] In an attempt to solve this problem and allow the capturing
and retaining of small calculi, so-called helical baskets were
devised. Examples of surgical extractors equipped with the helical
baskets can be found in U.S. Pat. Nos. 3,496,330; 6,190,394;
4,347,846.
[0010] It is appreciated in the art that helical baskets
incorporate strong, flexible wire construction in a spiraled shape
design. The streamlined, spiraled shape is well suited for
efficient, effective stone capture. As the basket is drawn back
over the entrapped calculi, the configuration of the wires "sweeps"
the stone into the basket.
[0011] U.S. Pat. No. 5,496,330 discloses a helical basket formed as
a plurality of strands encased in a sheath and wrapped in a helical
form. The displacement of a portion of the threads from the sheath
causes their wide angular disposition to form a basket for
retrieving the object. The threads include a plurality of
individual filaments that are closely spaced through the length of
the basket. By virtue of strands, formed as multiple, closely
situated adjacent wires, the number of contact points with
entrapped calculi is increased without requiring a concomitant
increase in the size of the overlying sheath.
[0012] Nevertheless, one can appreciate that the abovementioned
advantage associated with the increased number of contact points
may limit this basket to the treatment of small calculi and render
this basket less suitable for the immobilization of relatively
large calculi. The reason for this is the close angular disposition
of the filaments that prevents the entry of large calculi in the
limited open space between the adjacent filaments.
[0013] U.S. Pat. No. 6,190,394 discloses a medical retrieval basket
formed as a plurality of flexible elements that are outwardly
disposed to form a cage for entrapping objects therein. This basket
was devised to enable the efficient entrapment of the objects and
their reliable holding within the cage. To achieve this goal, the
basket is manipulated by rotation and employs flexible elements
having different sizes, different cross-sectional configuration
and/or different spacing.
[0014] In one embodiment, the cage consists of non-twisted flexible
elements as in flatware basket design. In the other embodiment the
flexible elements are helically twisted. In both embodiments, the
cage is symmetrical with respect to a plane drawn perpendicularly
to the middle of the cage length.
[0015] It can be appreciated, however, that the above-mentioned
intrinsic disadvantages associated with flatwire and helical
baskets would be characteristic also to the basket disclosed in
U.S. Pat. No. 6,190,394. The fishier disadvantage of the helical
design is associated with the fact that parallel-directed helically
shaped filaments are prone to entanglement.
[0016] U.S. Pat. No. 4,347,846 discloses a surgical extractor
employing a cage or basket formed by steel wires and disposed in a
helical path. Some of the wires follow a helix in clockwise
direction, while other wires, in equal number, follow a helix in
anti-clockwise direction. By virtue of this extractor, the
reliability of retention of the body during evacuation is improved,
since the body may enter within the extractor sheath when the cage
is being retracted. This prevents the accidental escape of the body
from the cage. Furthermore, by virtue of the opposite direction of
the helically shaped filaments, any danger of their twisting and
entanglement of the cage is avoided.
[0017] It should be emphasized that the general shape of the cage
employed in the extractor described in U.S. Pat No. 4,347,846 is
very similar to the shape of helical basket disclosed in U.S. Pat.
No. 6,190,394. This shape is also symmetrical to a plane, drawn
perpendicularly to the middle of the basket's length. Therefore,
the same above-mentioned intrinsic disadvantages are characteristic
to this helical basket as well. Furthermore, since the filaments
are not bound together and only have points of passive contact in
which they overlap, it can be appreciated that the cage will
neither have sufficient radial rigidity to prevent escape of the
calculi between adjacent filaments, nor sufficient dilatation
ability to provide enough room between the entrapped calculi and
the tissue of the passage. Thus, either the loss of calculi during
evacuation or damage to the adjacent tissue might occur during the
treatment.
[0018] In an attempt to overcome the disadvantages associated with
the entrapment and retention of calculi of various sizes, a
multi-wire parachute basket having two sections have been devised.
In the first section, the amount of filaments is small and they are
in spaced relationship to enable the easy passage of the calculi
through the spaces between the filaments. The second section is
formed as a plurality of filaments, extending from the filaments of
the first section and defining a multi-wire cage. Since in this
cage the filaments are in close relationship, it is possible to
ensure more complete engagement of the captured calculi when the
basket is in a protracted position and a more reliable grip when
the basket is being retracted within the sheath.
[0019] One early attempt to devise a basket in accordance with the
parachute concept is described in U.S. Pat. No. 3,472,230. This
patent discloses a retrieval basket made of four spring wires
connected to a slide. An umbrella made of suitable flexible web
material is connected to the distal ends of the wires so that upon
deployment of the basket the edges of the umbrella form a scraper.
Retracting the basket is associated with scraping the debris from a
body passage and its is retaining within the umbrella.
[0020] The other example of the retrieval parachute basket,
provided with web umbrella, is presented in U.S. Pat. No.
4,790,812. The disadvantage of the parachute baskets provided with
the web umbrella is associated with difficulty in manufacturing and
with the relatively large size of the web umbrella in the compacted
condition.
[0021] The further progress in the design of parachute baskets have
been achieved by devising multi-wire parachute baskets (see, for
example, S.U. Pat. No. 1036325; S.U. Pat. No. 202528, U.S. Pat. No.
6,168,603).
[0022] S.U. Pat. No. 1036325 describes a surgical extractor with
multi-wire parachute basket formed with a first section which is
proximal to the sheath and with a second section, which is distal
thereto. The proximal section comprises two separate branches
extending from the sheath in a V-shaped fashion. The branches
comprise strings that are woven from the individual wire filaments.
From distal ends of the branches emerge individual wire filaments,
which are bent as elongated elliptical loops. The loops emerging
from the branches meet in a common point at the distal end of the
extractor. Additional wire filaments are provided longitudinally
extending within the loops. These filaments divide the loops into
supplemental branches, which together define the second section of
the basket.
[0023] The disadvantage of this basket is associated with the fact
that it still does not always ensures reliable retention of the
calculi, since the amount of branches along the basket is invariant
and their filaments are parallel and separate. Thus, small calculi
might escape through the room between the branches of the second
section.
[0024] A similar construction of the multi-wire parachute basket is
disclosed in U.S. Pat. No. 6,168,603. In this U.S. patent is
described surgical extractor on whose distal end is arranged a
plurality of wires defining a retrieval basket. Each wire comprises
a first portion having an individual strand and a second portion
comprising a plurality of filaments. When a retaining sheath of the
extractor is retracted the wires formed of a shape memory material
expand. Each strand assumes a spaced relationship to define a first
section of the basket. A plurality of filaments define a second
section of the basket Widely spaced wires of the first section
promote capturing the object and closely spaced wires of the second
section enable retention of the captured object. It is worth
mentioning that in one of the embodiments the second section is
formed from filaments which are helically wound and angularly
spaced.
[0025] S.U. Pat. No. 202528 discloses a surgical extractor provided
with a basket formed from at least two branches made of metallic
stings. The main branches define the first section of the basket;
which is intended for entering the calculus within the basket. Each
branch forms at its distal end sub-branches, which are made of two
main sub-branch and one auxiliary sub-branch. The sub branches
define the second section of the basket. The sub-branches and the
auxiliary branches have different thicknesses and different
elasticities. By virtue of this basket, the reliability of
entrapment and immobilization of the entrapped calculus is
improved, since its construction allows for the variation of the
amount and arrangement of the sub-branches.
[0026] However, the above mentioned multi-wire parachute baskets
only partially solve the problem of reliable capturing,
immobilization and holding of calculi irrespective of their size.
The reason for his is the size of the open space along the
branches, which is equal to the length of filaments of the second
section. Calculi whose size is shorter than this length can easily
escape from the basket. Furthermore, in the above baskets the
filaments of neighboring branches are either fully separate (as in
S.U. Pat. No. 1036325) or only passively overlap (as in U.S. Pat.
No. 6,168,603, S.U. Pat. No. 2022528) and they are not entwined. By
virtue of this provision the radial rigidity of the cage is very
limited and might be not sufficient to prevent the possibility of
the adjacent filaments being spread apart by the calculus during
entrapment, and the calculus thus escaping. Insufficient radial
rigidity is associated also with the possibility of damaging
adjacent body tissues by the entrapped calculus protruding through
the open space formed by the spread filaments. The insufficient
radial rigidity deteriorates the dilatation ability of the whole
basket and therefore contributes to the possibility of damage
occurring to the nearby body tissues.
SUMMARY OF THE INVENTION
[0027] Despite the extensive prior art in the area of surgical
devices employing retrieval baskets for extracting objects from a
body, there is still a need in the art for, and it would be useful
to have a novel, convenient and safe surgical tool suitable for the
reliable and efficient extraction of foreign objects from the body
irrespective of the size of the object and its location within the
body.
[0028] It would also be advantageous to have a novel surgical tool,
provided with a retrieval basket defined by increased structural
rigidity and dilatation ability, thus reducing the probability of
traumatizing adjacent body tissues.
[0029] It would still be advantageous to have a novel and improved
surgical tool defined by easy and fist protracting and retracting
from the sheath and thus enabling more reliable functioning during
the surgical treatment.
[0030] It would yet be advantageous to have a novel and improved
surgical tool ensuring the adaptation to elastic properties of the
surrounding body tissues.
[0031] The aforementioned needs and advantages of the present
invention can be achieved in accordance with the following
combination of its essential features, referring to different
embodiments thereof as a surgical device and as a retrieval
basket.
[0032] According to one embodiment of the invention, there is
provided a novel surgical device for extracting objects from a body
including a retrieval basket and a basket control assembly.
[0033] The retrieval basket is suitable for entrapping the object
and retaining it during extraction. The basket comprises a Picture
having a proximal end and a distal end. The structure is formed by
a plurality of filaments fabricated from a single or several wires.
It should be noted that the wires selected for the construction of
the basket can be single-filament wires, or, when desired, can be
multi-filament wires.
[0034] The filaments extend between the proximal end and the distal
end. At least a part of the filaments, which originate from the
proximal end, can arrive at the proximal end after winding. At
least a part of the filaments are configured in the form of loops.
At least a part of the loops are interlaced so as to define a net
at the distal end, and thereby impart structural rigidity and
dilatation ability to the basket when opened.
[0035] According to one embodiment of the invention, the size of
holes (cells) of the net decreases from the proximal end towards
the distal end. In other words, the density of the net increases
from the proximal end to the distal end of the structure.
[0036] According to one embodiment of the invention, the filaments
in a region of the structure at the proximal end form at least two
strands, each including a plurality of the filaments. According to
this embodiment the structure of the basket has a parachute-like
shape, i.e., a form of the basket is symmetrical along the basket
central axis.
[0037] According to another embodiment of the invention, the
filaments in a region of the structure at the proximal end form a
plurality of strands and one of the strands is common for all the
filaments. The structure of the basket, according to this
embodiment, has a spoon-like shape.
[0038] The basket control assembly is suitable for bringing the
basket to the object and is adapted for manipulating the basket.
The basket control assembly includes a catheter in the form of a
tubular heath to be inserted within the body. The catheter is
suitable either for retracting the basket within the sheath, to
enable bringing the catheter within the body, or for protracting
the basket from the sheath to enable open of the basket.
[0039] According to one embodiment of the invention, the filaments
are made of metallic material. The metallic material can be
selected from NiTi based alloy, (e.g., Nitinol) and stainless
steel.
[0040] According to another embodiment of the invention, the
filaments are made of non-metallic material e.g. Capron.
[0041] According to yet embodiment of the invention the filaments
are made of a material that has thermo-mechanical shape memory
characteristic. The surgical device, according to this embodiment,
comprises a controllable power supply source coupled to the
filaments for passing an electric current therethrough. This
electric current should be capable of heating filaments and thereby
cause the filaments to change their shape due to the heating. The
filaments of the basket can be covered by an insulating layer. The
insulating layer can, for example, be made of Teflon.
[0042] The surgical device of the present invention has many of the
advantages of the aforementioned techniques, while simultaneously
overcoming some of the disadvantages normally associated
therewith.
[0043] For example, since the basket of the present invention has
an asymmetric net shape, the proximal net holes are bigger than the
distal net holes. This shape ensures easy stone capture (through
the distal end), and on the other hand, ensures foolproof
extraction without loss of the stone (through the proximal
end).
[0044] The structure of the basket of the stone extractor allows to
increase their springiness and flexibility that, in turn, allows to
decrease their traumatic influence on the organ. Such an effect is,
inter alia, achieved by the manner in which the NiTi wires are
twisted and interlaced. Such superelasticity allows to treat the
organ better in the case of small stones, thus, e.g., minimize the
damage of the urinary tract tissue.
[0045] The surgical device according to the present invention may
be easily and efficiently manufactured and marketed.
[0046] The surgical device according to the present invention is of
durable and reliable construction.
[0047] The surgical device according to the present invention may
have a low manufacturing cost.
[0048] Thus, in accordance with one broad aspect of the invention,
there is provided a retrieval basket for entrapping and retaining
an object located in a body for its extraction therefrom, the
basket comprising a structure having a proximal end and a distal
end, and constituted by a plurality of filaments extending from the
proximal end towards the distal end and being in the form of
loops,
[0049] characterized in that at least a part of the loops are
interlaced so as to define a net at least at the distal end,
thereby imparting structure rigidity and dilatation abilities to
the basket when opened.
[0050] In accordance with another one broad aspect of the
invention, there is provided a surgical device for removing a
foreign object from a body, comprising:
[0051] a retrieval basket for entrapping and retaining an object
located in a body for its extraction therefrom, the basket
comprising a structure having a proximal end and a distal end and
constituted by a plurality of filaments extending from the proximal
end towards the distal end and being in the form of loops;
[0052] at least a part of the loops are interlaced so as to define
a net at least at the distal end, thereby imparting structural
rigidity and dilatation abilities to the basket when opened;
and
[0053] a basket control assembly coupled to the basket, comprising
a tubular sheath adapted to penetrate into the body for reaching
the object, and a manipulator for manipulating the basket for
extraction the object from the body, the assembly is configured for
retracting the basket within the sheath and protracting the basket
therefrom for its opening.
[0054] There has thus been outlined, rather broadly, the more
important features of the invention in order that the detailed
description thereof that follows hereinafter may be better
understood. Additional details and advantages of the invention will
be set forth in the detailed description, and in part will be
appreciated from the description, or may be learned by practice of
the invention.
BRIEF DESCRIPTION OF THE DRAWINGS
[0055] In order to understand the invention and to see how it may
be carried out in practice, a preferred embodiment will now be
described, by way of non-limiting example only, with reference to
the accompanying drawings, in which:
[0056] FIG. 1A is a schematic view of a longitudinal cross-section
of a surgical device, according to one embodiment of the preset
invention;
[0057] FIG. 1B illustrates an example of a basket in which the
filaments form a pushing cable.
[0058] FIG. 1C illustrates two examples of the cross-section (A-A
in FIG. 1A) of the basket woven from a single length of wire o from
several wires.
[0059] FIGS. 2A-2D illustrate various views of the basket provided
with two branches, according to one embodiment of the
invention;
[0060] FIGS. 3A-3D illustrate various views of the basket provided
with three branches, according to another embodiment of the
invention;
[0061] FIGS. 4A-4D illustrate various views of the basket provided
with three branches, each of which is configured with two loops,
according to still another embodiment of the preset invention;
[0062] FIGS. 5A-5D illustrate various views of the basket provided
with four branches, each of which is equipped with one loop,
according to yet another embodiment of the preset invention;
[0063] FIGS. 6A-6D illustrate various views of the basket shown in
FIGS. 5A-5D in which the loops are configured in an 8-like fashion,
according to one embodiment of the preset invention;
[0064] FIG. 7 is a schematic view of a longitudinal cross-section
and a top view, respectively, of a basket according to still
further embodiment of the invention.
[0065] FIG. 8 is a schematic view of a longitudinal cross-section
and a top view, respectively, of a basket according to yet another
embodiment of the invention.
[0066] FIG. 9 is a schematic view of a longitudinal cross-section
and a top view, respectively, of a basket according to still
further embodiment of the invention.
[0067] FIG. 10 is a schematic view of a basket according to yet
further embodiment of the invention;
[0068] FIG. 11 is a schematic view of a basket according to yet
further embodiment of the invention;
[0069] FIGS. 12A-12F illustrate schematically examples of how
distal ends of the loops are intertwined; and
[0070] FIG. 13 is a schematic view of a system for control of a
surgical device with a basket made of a material with
thermo-mechanical shape memory effect, according to one embodiment
of the preset invention.
DETAILED DESCRIPTION OF THE INVENTION
[0071] The principles and operation of the surgical device
according to the present invention may be better understood with
reference to the drawings and the accompanying description, it
being understood that these drawings and examples in the
description are given for illustrative purposes only and are not
meant to be limiting.
[0072] Referring to FIG. 1A, a general schematic view of a surgical
device 100 devised for the retrieval of various calculi or other
objects from a human or animal body during the treatment of
biliary, urinary or other systems is shown, according to one
embodiment of the invention. Such treatment may include the
extraction of stones from the urethra (e.g., cystic calculus and
ureteral calculus), as well as bile duct (choledochal) stone,
biliary calculus, etc. It should be appreciated that the device 100
can also be used in other surgical treatments in combination with
other surgical instruments and equipment, (e.g. for the destruction
of calculi, etc.).
[0073] The device 100 of the invention comprises a retrieval basket
portion 112 and a control means portion 114. The retrieval basket
portion 112 is suitable, inter alia, for the immobilization of the
object to be evacuated and its retention during extraction. The
control means portion 114 is suitable for manipulating the
retrieval basket portion 112.
[0074] The control means portion 114 includes a flexible tubular
catheter 116, configured as a sheath, adapted to penetrate along
the body passages near the location of the object (not shown) and a
manipulator 120.
[0075] The retrieval basket portion 112 includes a retrieval basket
115 that is coupled to a pushing element 118 (e.g., rod, cable or
wire), for example, via a connector (not shown). The pushing
element 118 is arranged within the catheter and connected to the
manipulator 120.
[0076] In practice, a surgeon can manipulate the pushing element
118 by virtue of the manipulator 120, and thus the basket 115 can
be either retacted within the catheter 116 or protracted therefrom.
The surgeon, by holding the manipulator 120, can also maneuver the
catheter 116 within the body organ (not shown), (e.g. to displace
it by turning, pushing, or pulling).
[0077] In practice, the surgeon moves the catheter behind the
object to be extracted, and then protracts the retrieval basket
portion 112 from the catheter 116. Once the basket 115 is
protracted it opens due to its resiliency and is ready for
receiving the object to be entrapped therein. The surgeon pulls the
pushing element 118 together with the retrieval basket portion 112
until the basket 115 entraps the object, and thus extracts the
entrapped object from the body.
[0078] The retrieval basket 115 comprises a structure having a
proximal end 128 and a distal end 136 and is formed by a plurality
of filaments fabricated from a single length of wire or several
wires. The filaments extend from the proximal end 128 towards the
distal end 136.
[0079] As was noted above, the filaments of the retrieval basket
115 can be coupled to the pushing element 118 that is provided as a
separate unit at the proximal end 128. Alternatively, the filaments
can be bound together (e.g., glued, soldered, weld, etc.) at the
proximal end 128 and extended towards the manipulator. In such a
case the filaments bound together form the pushing element 118. An
example of such a configuration is shown in FIG. 1B.
[0080] Referring to FIG. 1C, two examples of cross-section (A-A in
FIG. 1A ) of the basket near the proximal end 128 are
illustrated.
[0081] According to the first example, a cross-section 150 is
formed of filaments 151 woven from a single length of wire or from
several wires that enter into the cross-section from the left side
and leave the cross-section in a whole number from the right side.
these filaments 151 themselves can form a pushing cable (118 in
FIG. 1A).
[0082] According to the second example, a cross-section 160 is
formed of filaments woven from a single length of wire among which
only filaments 153 and 154 enter into the cross-section 150 from
the left side and leave the cross-section from the right side,
whereas filaments 155 enter into the cross-section 160 from the
left side, turn around and leave the cross-section also from the
left side, The basket utilizing this configuration of the filaments
can be coupled to the pushing element 118 (provided as a separate
unit) at the right end of the cross-section 160. For this
configuration, the filaments 153 and 154 can be arranged within the
catheter 116, coupled to the manipulator 120 and used for
extraction of the basket from the body in case of emergency, e.g.,
when the pushing element is torn off from tie basket.
[0083] Turning back to FIG. 1A, the basket 115 can be divided into
a first section 122, which is proximal to the control means portion
114, and a second section 124, which is distal thereto. According
to the embodiment shown in FIG. 1A, in the first section 122 the
filaments form strands 126 arranged in branches. Hereinafter, the
terms "strands" and "branches" in the context of this description
are used interchangeably. The filaments in the strands 126 are
entwined and spatially arranged in such manners that upon
protracting from the catheter 116 (sheath) they can be readily
spread out. The filaments meet in the proximal end 128, where the
retrieval basket 115 is connected to the pushing element 118.
[0084] In the second section 24 the strands ramify at branching
points 141, 142, 143 and form loops 134. At least a part of the
loops 134 are interlaced so as to define a net forming a shape of
the statue near the distal end 136. It should be appreciated that
the net formed thereby has a hole (cell) size decreasing from the
proximal end towards the distal end. The net formed thereby imparts
structural rigidity and dilatation ability to the basket when it is
opened.
[0085] In the open condition, the first section 122 of the basket
115 has relatively large open spaces 130 and 132 left between the
adjacent branches. It can be easily appreciated that by virtue of
the open spaces 130 and 132, the immobilization of the object and
receiving thereof inside the first section 122 becomes easy and
convenient during the first stage of the treatment, when the
surgeon begins pulling the basket 115 for entrapping the
object.
[0086] In the embodiment of the invention shown in FIG. 1A, the
strands are arranged in three branches and define the first section
122 of the basket 115. It should be appreciated that in practice
only two branches might be sufficient to define the first section
122.
[0087] According to one embodiment of the invention, the loops 134
are configured from the same wire filaments from which the branches
are entwined. It is possible however that the loops are made of
separate wire filaments and connected to the respective branches,
e.g. by soldering.
[0088] According to one embodiment of the invention, the most
distal ends of the loops 134 are bound together (e.g., by a
bushing) at the distal end 136 to form a tip. It should be
appreciated that when desired, after the tip, the wire filaments
can be intertwined to form a guiding rod 138. The guiding rod 138
can function as a guide to facilitate the displacement. of the
retrieval basket portion 112 as well as to facilitate the
penetration and movement of the whole surgical device 100 within
the body organs.
[0089] As was noted above, at least a part of the loops 134 are
overlapped and interlaced. The overlapped and interlaced wire
filaments define collectively the second section 124 of the basket
115. It should be appreciated by a person versed in the art that
the interlaced loops intertwine one with another. At least a part
of the filaments, which originate from the proximal end 128, can
arrive at the proximal end after winding, By virtue of this
arrangement, the second section 124 of the basket 115 is configured
as a pet, having a cell structure with relatively small cells 140,
suitable to retain relatively small objects reliably entrapped
therein.
[0090] According to one embodiment of the invention, the size of
the cells of the net decreases towards the distal end 136. In other
words, a density of the net increases from the proximal end 128 to
the distal end 136 of the structure.
[0091] It has been empirically revealed that this net structure has
improved radial rigidity and dilatation ability, thus rendering the
whole basket to be less traumatic.
[0092] The retention ability of the basket depends on the size and
shape of the cells, which, in turn, can be controlled by the size
of the loops, their amount and spatial arrangement of their distal
ends. These features of the invention will be described and
illustrated below with reference to further drawings. Furthermore,
although it is not shown specifically in the drawings it should be
understood that in accordance with the invention the amount of
loops emerging from each branch can be similar or dissimilar, and
so their size.
[0093] It should be appreciated that the stands and loops can be
configured from filaments made of metallic or non-metallic (e.g.,
plastic) material having sufficient elasticity to enable opening
the basket when it is protracted from the sheath. This material
should be also biologically inert. Example of the materials
appropriate for the filaments include, but are not limited to,
stainless steel, superelastic TiNi alloy and Capron. It is also
recommendable to coat metallic wire filaments by an inert coating,
e.g. Teflon.
[0094] Referring to FIGS. 2A-2D, various projections of the
configuration of a retrieval basket 200, in accordance with another
embodiment of the invention, will be described in more detail. In
this embodiment, which in general is similar to the embodiment
shown in FIG. 1A, only two strands 202, 204 define the first
section of the basket 200 and thus a relatively large open space is
available between the branches enabling easy immobilization of
large calculi. The strand 202 ramifies at branching points 220 and
221 land provides a respective couple of loops 206, 208. In a
similar manner, the strand 204 ramifies at branching points 230 and
231 and provides a respective couple of loops 210, 212. The loop
206 is less than the loop 208, and the loop 210 is less than the
loop 212. These loops overlap and interlace in several points. For
the sake of simplicity, only two points, namely 214 and 216 are
designated in FIG. 2B to show the interlacement of the wires, from
which the loops 210 and 206, respectively, are configured.
[0095] It can be appreciated that by virtue of this spatial
arrangement a net-like structure is formed, consisting of small
cells, two of which are designated in FIG. 2B by numerals 218 and
220. It should be appreciated that by virtue of loops having
dissimilar size it is possible to form additional cells without
introducing new branches.
[0096] It should be understood that since the wire filaments (from
which the loops are made) are interlaced an additional structural
rigidity to the net-like structure is submitted. Hence, by virtue
of this configuration, very reliable retention of the entrapped
object (e.g., calculi) is ensured when it is extracted from the
body.
[0097] According to this embodiment of the invention, the retrieval
basket 200 has a first section, defined by strands 202, 204, and a
second section, defined by loops 206, 208, 210, 212, forming net
cells. For example, the length of the first section can be about
2/3 of the total basket length, i.e., the length of the second
section can be about 1/3 of the total length. This relationship of
the length is schematically shown in FIG. 2B, where the symbol L
designates the total basket length.
[0098] The strands 202 and 204 are bound together at a basket
proximal end 240 to form a cable 241. The cable 241 is coupled to a
pushing element 242 (see FIG. 2D) to extend the length of the cable
241.
[0099] Another embodiment of the invention is illustrated in FIGS.
3A-3D. Here, three similar strands 310, 312, 314 define the first
section of a basket 300. The strands 310, 312, 314 ramify at
branching points 350, 351, 352 and provide loops 316, 318, 320,
emerging from the branching points 350, 351, 352, The loops
spatially overlap and interlace in several points. As can be seen
in FIG. 3D, the loops 316 and 318 interlace in. points 322 and 324,
the loops 320 and 316 interlace in points 326, 328 and the loops
320, 318 interlace in points 330, 332. By virtue of this provision,
a net-like structure is formed including several cells, some of
which are designated in FIG. 3D by numerals 334, 336, 338, 340. The
loops and cells is collectively define second section of the basket
300, in which the entrapped object can be reliably retained during
extraction. Similarly to the previous embodiment, since at least
some of the individual wire filaments, from which the loops are
made are interlaced, a net-shaped structure is formed, thereby
imparting improved rigidity to the basket structure.
[0100] Referring now to FIGS. 4A-4C, still another embodiment of
the retrieval basket is illustrated. According to this embodiment,
a retrieval basket 400 includes three strands 402, 404, 406. Each
branch is made of four entwined wire filaments. The branches 402,
404, 406 ramify at branching points and provide interlaced loops.
For example, the stand 402 ramifies at a branching point 420 into
strands 25 431 and 432. In tun, the strands 431 and 432 ramify at
the branching points 422 and 424 and thus for loops 416 and 418,
respectively. One of the loops (e.g., the loop 416) has a regular
shape, while the other loop (e.g., the loop 418) is twisted and has
an 8-shape configuration.
[0101] According to another example, as seen in FIGS. 4A and 4B,
the wire filaments 408, 410, 412, 414 emerge from a branching point
421 of the strand 406. The filaments 408 and 410 form regular loop,
while the two other filaments 412 and 414 are twisted and form an
8-shaped loop.
[0102] The wire filaments are overlapped and some of the loops are
interlaced and form a net. It is seen, for example in FIG. 4A, that
the filament 410 of the loop referring to the strand 406 interlaces
with the filaments 416, 418 of two loops emerging from strand 402.
By the same token, the filament 416 of the loop referring to the
strand 402 interlaces with the wire filaments 410 and 412 of the
loop emerging from the strand 406.
[0103] It can be readily appreciated that by; virtue of this
arrangement the whole second section of the basket becomes a net,
having a densely meshed structure since twisted loops also
contribute to the formation of cells. The cells formed by the
intersection of the distal ends and the cells formed due to
twisting collectively define the net-shaped structure which is
especially suitable for reliable retention of small objects or
calculi. At the same time, sufficient space is still reserved
between the branches to allow easy entrapment of relatively large
objects or calculi.
[0104] Referring to FIGS. 5A,-5D, yet another embodiment of the
invention is illustrated. As can be seen in FIG. 5A, a basket 500
has a first section, defined by four strands 510, 512, 514 and 516.
Each strand is provided at the distal end thereof (i.e. at
branching points 531, 532, 533, 534) with a corresponding loop,
each loop having an elongated shape. One such loop emerging from
the strand 512 is designated in FIG. 5B by a numeral 517. Distal
ends of the loops are interlaced with the formation of a plurality
of small cells. Some of the cells are designated by numerals 518,
520, 522, 524, 526, 528. The cells together with the loops define
spatially a second section of the basket 500. It should be
understood that similarly to the previous embodiments, since the
loops are interlaced, such a net-shaped structure renders the
resulting structure additional structural rigidity.
[0105] Referring to FIGS. 6A-6E, still a flirter embodiment of the
invention is shown. Accordingly, four strands 610, 612, 614, 616,
which are provided at the distal ends thereof with corresponding
loops 618, 620, 622, 624, form a basket 600.
[0106] The loops 618, 620, 622, 624 are provided with dissimilar
shapes. Furthermore, the loops are bent in such a manner that
additional small loops are formed at the distal end of each loop.
FIG. 6E shows one such loop 618 that emerges from the strand 610
and terminates at the place from which an additional small loop 626
emerges.
[0107] For example, the additional loops are provided with a
circular shape and they overlap and interlace, thus defining the
dense net-like structure of the second section of the basket.
[0108] It can be readily appreciated that by providing the loops
with various shapes it is possible to vary also the size and shape
of the cells, formed at the intersection of the loops, thus control
the retention ability of the basket.
[0109] Referring now to FIG. 7, still a further embodiment of the
invention is illustrated. According to this embodiment, a retrieval
basket 70 includes four strands configured in branches. Only three
such strands 71, 72 and 73 can be seen in FIG. 7. Each so is formed
of four entwined wire filaments. These strands ramify at branching
points 74, 75, 76 and result in interlaced loops. For example, the
strand 72 roes at the, branching point 75. The filaments 77 and 78
that emerge from the branching point 75, form two corresponding
loops. A branch 19 consisting of two remaining entwined filaments
also emerges from the branching point 75. The branch 79 ramifies at
a branching point 703 and provides a loop formed of the filaments
701 and 702. According to this embodiment of the invention, the
loops formed thereby are interlaced so as to form a net
structure.
[0110] Referring now to FIG. 8, yet another embodiment of the
invention is illustrated. According to this embodiment, a retrieval
basket 80 includes four strands configured in branches. Only three
such strands 81, 82 and 83 can be seen in FIG. 8. Each strand is
formed of four entwined wire filaments. The strands 81, 82 and 83
ramify at branching points 84, 85, 86 and result in interlaced
loops. For example, the strand 82 ramifies at the branching point
85 into two branches 87 and 88, consisting of two entwined
filaments. In turn, the branches 87 and 88 ramify at branching
points 801 and 802, and provide loops formed of filaments 803, 804,
805 and 806, respectively. According to this embodiment of the
invention, the loops formed thereby are interlaced so as to form a
net structure.
[0111] Referring now to FIG. 9, still a further embodiment of the
invention is illustrated. According to this embodiment, a retrieval
basket 90 includes four strands configured in branches. Only free
such strands 91, 92 and 93 can be seen in FIG. 9. Each sand is
formed of four twined wire filaments. These strands ramify at
branching points 94, 95, 96 and result in interlaced loops. For
example, the strand 92 ramifies at the branching point 95 into the
loops formed of filaments 901, 902, 903 and 904. According to this
embodiment of the invention, the loops formed thereby are
interlaced so as to form a net structure.
[0112] Referring now to FIG. 10, still a further embodiment of the
invention is illustrated. According to this embodiment, a retrieval
basket 1000 comprises a spoon-like structure having a proximal end
1001 and a distal end 1002 and formed of a plurality of wire
filaments. In a region of the structure at the proximal end, the is
filaments are bound and form a plurality of strands 1003. The
filaments extend from the proximal end towards the distal end and
are configured in the form of interlaced loops so as to form a net
structure. The filaments, which originate from the proximal end,
arrive at the proximal end after winding. According to this
embodiment, one strand (a strand 1004) of the plurality of strands
1003 is common for all the filaments.
[0113] Referring now to FIG. 11, still a further embodiment of the
invention is illustrated. According to this embodiment, in addition
to the structure of the basket 1000 shown in FIG. 10, a structure
of a retrieval basket 1100 further includes a supporting cable 1101
connected to a strand 1103 for imparting additional structural
rigidity to the basket when it is opened. For example, the
supporting cable 1101 can include one ore more filaments and be
connected to strand 1103 at a distal end 1102.
[0114] Referring now to FIGS. 12A-12F, it will be explained how
individual wire filaments, from which the loops are made, could
overlap and/or interlace. Note that the term "overlap" herein is
assigned to such arrangement of the filaments, in which one element
passes through the perpendicularly directed filament, i.e., one of
the filaments is always over or under the other filament. The tern
"interlace" herein is assigned to the situation when at least one
filament interweaves with the perpendicularly directed filaments,
i.e., one of the filaments passes first above the perpendicularly
directed filament and then passes under the next perpendicularly
directed filament.
[0115] In FIGS. 12A-12F different patterns corresponding to a
possible arrangement of individual filaments defining the cells are
shown schematically and with exaggeration. For the sake of
simplicity, the wire filaments are depicted as vertical and
horizontal bands overlapping at a right angle and defining
orthogonal pattern, consisting of four vertical arid four
horizontal bands. However, it should be understood that in reality,
thin wire filaments form the cells. The filaments are directed with
respect to each other not necessarily at a right angle, and their
amount is not limited to a four by four pattern.
[0116] FIG. 12A shows a pattern in which all wire filaments
interlace one with another, i.e. each horizontal wire filament
interlaces with all vertical filaments and vice versa. It is seen,
for example, that a vertical filament 710 goes first under a
horizontal filament 712, then above a horizontal filament 714, then
again under a horizontal filament 716 and finally again above a
horizontal filament 718. On the other hand the horizontal filament
712 goes first above the vertical filament 710, then under a
vertical filament 720, then again above a vertical filament 722 and
then again under a vertical filament 724. The rest of filaments are
arranged similarly.
[0117] FIG. 12B depicts another situation, in which the filaments
both interlace and overlap with intersection. It is seen that a
vertical filament 726 interlaces with horizontal filaments 728,
730, 734 and overlaps with the perpendicularly directed filament
732.
[0118] In FIG. 12C is shown still a new pattern, consisting of
overlapped and interlaced filaments. It is seen for this example
that two neighboring vertical filaments 736, 738 go under two
neighboring horizontal filaments 740, 742 and then go above two
next horizontal filaments 744, 746.
[0119] FIGS. 12D-12F show Per possible patterns, consisting of
overlapped and interlaced filaments. In particular, in the pattern
shown in FIG. 12F, each filament overlaps with three perpendicular
filaments and interlaces with only one filament.
[0120] It can be appreciated that the patterns depicted in FIG. 12A
and FIG. 12F represent two extreme situations, corresponding
respectively to the pattern in which all filaments are interlaced
and to the pattern in which only one filament is interlaced, while
the other filaments are overlapped.
[0121] Having explained various cells patterns, in which the
filaments of the loops might be arranged, still another embodiment
of the surgical device of the invention will be disclosed.
According to this embodiment, a process of opening the baskets
having the topology described above is ensured not by elasticity of
the material of the filaments as in the previous embodiments, but
by virtue of the thermo-mechanical shape memory characteristic of
the material from which the filaments are made. An example of such
a material is a super elastic alloy based on Ni and Ti, like
Nitinol (e.g., Nitinol SE508 Wire commercially available from
Nitinol Devices & Components) or any other suitable
commercially available alloy having shape memory ability,: i.e. the
ability to return to some previously defined shape or size when
subjected to the appropriate thermal procedure.
[0122] Referring to FIG. 13, a schematic view of a system for
control of a surgical device 1300 with a basket made of a material
with thermo-mechanical shape memory effect is shown, according to
one embodiment of the preset invention. An example of such a
material is Nitinol SM495 Wire commercially available from Nitinol
Devices & Components. It should be noted that the blocks in
FIG. 13 are intended as functional entities only, such that the
functional relationships between the entities are shown, rather
than any physical connections and/or physical relationships.
[0123] According to this embodiment of the invention, the system
includes a retrieval basket 1301 and a basket control means 1302.
The basket control means includes a controllable power supply
source 1303 coupled to filaments of the basket 1301 for passing an
electric current therethrough that is capable of causing them to
change their shape due to heating. The manner of coupling the power
supply source 1303 to tie filaments and control of the surgical
device is known per se (see, for example, WO 92/16153), and
therefore will not be expounded hereinbelow.
[0124] According to one embodiment of the invention, the filaments
of the basket are covered by an insulating layer. The insulating
layer can, for example, be made of Teflon. The advantage of Teflon
is its thermal resistance and low coefficient of mechanical
friction, which leads to an additional reduction of traumatism.
Furthermore, manufacturing of the basket filaments from Nitinol
renders the whole basket ability to undergo reversible deformation
up to 10%, which is close to the dilatation ability of living
tissues. It can be readily appreciated that a basket made of
Nitinol becomes compatible both biologically and mechanically with
the is adjacent tissues, since it is more capable of coping the
topography of the organ in which the basket resides. By virtue of
improved compatibility the basket becomes less traumatic. Still a
further advantage of using Nitinol is associated with the
"superelastic" properties of this material and the capability of
this alloy to improve its "rigidity" when the temperature
increases. Introducing of a catheter with deployed therein Nitinol
basket into a body organ, having a temperate higher than the
ambient temperature increases elasticity of the basket and its
dilatation ability, which improves the ability of the basket to
reliably entrap and retain the object or calculi to be retrieved.
It should be also mentioned, that due to the "superelastic"
properties of Nitinol, surgical extractors employing baskets made
of this material have a longer service life than Factors with
baskets made of stainless steel.
[0125] It can be appreciated that by virtue of the above-described
construction of the retrieval basket, provided with overlapping
loops, the whole surgical apparatus of the present invention
becomes very simple, inexpensive, easy and reliable in operation.
The surgical tool of the invention is capable of conveniently
entrapping and reliably retaining both small and large objects and
at the same time, it is less traumatic due to basket's improved
structural rigidity and dilatation ability.
[0126] As such, those skilled in the art to which the present
invention pertains, can appreciate that while the present invention
has been described in terms of preferred embodiments, the concept
upon which this disclosure is based may readily be utilized as a
basis for the designing of other structures and processes for
carrying out the several purposes of the present invention.
[0127] It should be understood that the device of the present
invention is not limited to the urological treatment of a human
body. It can be successfully employed for surgical treatments of
animals as well. Furthermore, the present invention is not limited
strictly to extracting calculi during urological treatment. It is
suitable for other surgical treatments, which might require
retrieval of foreign objects from the body systems, e.g. from blood
vessels etc.
[0128] Moreover, the present invention is not limited to medical
devices, and the extractor device can be used to extract any type
of article from a wide range of inaccessible locations such as
inside a pipe or tube (for example, the waste outlet of a domestic
sink) or inside a chamber within a large piece of machinery which
would be difficult to dismantle.
[0129] Also, it is to be understood that the. phraseology and
terminology employed herein are for the purpose of description and
should not be regarded as limiting.
[0130] It is important, therefore, that the scope of the invention
is not construed as being limited by the illustrative embodiments
set forth herein. Other variations are possible within the scope of
the present invention as defined in the appended claims and their
equivalents.
* * * * *
References